The invention relates to an anti-noise device for a vehicle fuel tank, in particular for cars.
A vehicle""s successive braking and restarting maneuvers cause translations of the fuel mass in the tank that the driver perceives in the form of noises with a shock effect. In particular, these noises happen when the level of fuel reaches a fraction of the total capacity of the tank.
We know of fuel tanks in particular through document FR 2,638,127 that contain rigid anti-noise partitions on the bottom of the tank or/and on the side walls of the tank. We also know through document FR 2,587,979 of tanks whose walls are distorted so as to form stiffening ribs and/or anti-lapping ribs.
However, we have noticed that this type of device does not resolve the lapping noise problems in the tank in a satisfactory manner. We also know of fuel tanks that contain rigid anti-noise partitions that are attached to the tank""s upper wall and linked to another rigid partition attached to the bottom of the tank in order to create a baffle effect. Also, we know of rigid pierced partitions that extend over the entire height of the tank. Lastly, U.S. Pat. No. 2,806,622 describes a tank in which is arranged a support plate that is more or less horizontal and pierced. Two vertical breaking walls for the liquid, respectively upper and lower, are attached to the median part of the support plate.
However, none of these anti-noise devices are any more efficient in resolving the lapping noise problems in the tank.
One goal of this invention is to propose an anti-noise device for a vehicle fuel tank that compensates for all or part of the above-mentioned disadvantages of the prior art.
This goal is reached by the fact that the anti-noise device for a vehicle fuel tank, in particular that of a car, contains at least one partition located in the tank. This partition is flexible, is roughly located in the upper half of the tank and is roughly perpendicular to the preferred direction of the displacement of the fuel mass in the tank where the dimensions of the partition cross-wise in relation to the direction of the preferred displacement of the fuel mass are less than the tank""s wall spacing located across from the extremities of the partition in order to allow the partition to distort and bend during the ebbs and flows of the fuel.
According to another special feature, the partition is roughly located in the center part of the tank.
According to another special feature, in the case of a tank that is roughly parallelepiped and whose longitudinal symmetry axis is roughly parallel to the vehicle""s median longitudinal axis, the partition is roughly perpendicular to the bottom of the tank and to the vehicle""s median longitudinal axis.
According to another special feature, the dimensions of the partition in a direction perpendicular to the bottom of the tank are in the range of half the inside height of the tank.
According to another special feature, the dimensions of the partition cross-wise in relation to the preferred direction of the displacement of the fuel mass are less that the spacing of the walls of the tank located across from the extremities of the partition with a value ranging between 0.5 and 5 cm and preferably between 1 and 2 cm.
According to another special feature, the partition is attached to a fixed part of the tank by at least one point located in the median part of the partition that is contained in a plane that is roughly perpendicular both to the bottom of the tank and to the partition, to allow the two free extremities of the partition to bend under the action of the ebbs and flows of the fuel.
According to another special feature, the partition is attached at its upper part to the upper face of the tank or/and to a mechanism that measures the level of the fuel or a fuel pumping system that is located in the tank.
According to another special feature, the partition is attached at its lower part to the upper part of a fuel trap arranged on the bottom of the tank.
According to another special feature, the partition has a thickness ranging between a few tenths of a millimeter and a few millimeters, and is preferably of 2 mm.
According to another special feature, the flexible partition is made of the same material as the tank.
Other characteristics and advantages of the invention will become apparent upon reading the detailed description that will follow. In order to understand this description, we will refer to the attached figures, where: